php - 替换多个相同的字母

Question

我需要将多个相同的字母(只有 A-Z 或 a-z，而不是数字)连续替换为相同的三个。谁能帮我一个模式字符串？

例子:

Input: NO MEK PUCES CUDAK AVVVVVVVVVVVVVVVVVVVVVVVVV VASMAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

Output: NO MEK PUCES CUDAK AVVV VASMAAA

Answer 1

使用组 (([A-Za-z])) 和反向引用 (\1)。

$text = "NO MEK PUCES CUDAK AVVVVVVVVVVVVVVVVVVVVVVVVV VASMAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";    
echo preg_replace('/([A-Za-z])\1{3,}/', "$1$1$1", $text);
# => NO MEK PUCES CUDAK AVVV VASMAAA